Below is Esper, a rubberband powered 3D printed blaster. It uses half length darts and either Talon or Katana magazines. These are for sale on Etsy and are easy to put together. $110 shipped to Canada including exchange.
I printed mine and bought the hardware for $40
I used fimament from 3D printing Canada. Very happy with them. Here is a review
If any of you haven't heard of 3D printing Canada. I just want to let you know my experience with them. I've received two large orders of filament from them. One of the orders I had to order a 2kg em roll of black filament because they were out of the one kilogram rolls. I've had nothing but issues with the 2kg draw constantly breaking before the extruder. I've had zero issues with the one kilogram rolls both the value pla as well as the more expensive rolls. I sent them an email yesterday explaining the situation and within a few hours received an apology email asking for the product number. Today I received another email confirmation of them shipping me replacement filament free of charge. Simply an amazing company with fantastic customer service. Because of this they will be getting all of my business from now on.
If you are interested in a build or any Nerf 3D printed parts. Please feel free to contact me.